Device for generating high pressures and temperatures

ABSTRACT

A device for generating high pressures and temperatures, in which in the pressure chamber of a high strength metallic pressure container, a charge of material laterally surrounded by electrically insulating material by means of two piston rams movable in opposite direction with regard to each other and sealed relative to the pressure container is subjected to pressure while being electrically heated. The pressure container comprises at least two axially aligned metallic ring members of high strength hard metal which define a pressure chamber, while between the rings and between the rings and a matrix surrounding the rings, pressure resistant electrically insulating material is provided. Outside the pressure chamber, sealing means of plastically deformable strong metallic material are provided between the piston rams and the rings.

[451 July 22,1975

United States Patent [1 1 Biermann et al.

3,727,028 4/1973 Kuratomi.............................. 425/77 DEVICEFOR GENERATING HIGH PRESSURES AND TEMPERATURES [75] Inventors: KlausBiermann; .liirgen Burbach; Primar Examinerfijames Jones Horst Gimpel;Burckhard zirpins, Attorney, Agent, or Fzrm-Walter Becker all of Essen,Germany Assignee: Fried. Krupp Gesellschaft mit [57] ABSTRACT A devicefor generating high pressures and temperatures, in which in the pressurechamber of a high strength metallic pressure container, a charge ofmatebeschrankter Haftung, Essen, Germ any [22] Filed: 1973 riallaterally surrounded by electrically insulating ma- 21 Appl. No.:353,738

terial by means of two piston rams movable in opposite direction withregard to each other and sealed rel- A ative to the pressure containeris subjected to pressure [30] A gg l g n piglcauon Pnonty Data whilebeing electrically heated. The pressure container pr.ermany............................

2220349 comprises at least two axially aligned metallic ring members ofhigh strength hard metal which define a pressure chamber, while betweenthe rings and between the rings and a matrix surrounding the rings,ressure resistant electrically insulating material is rovided. Outsidethe pressure chamber, sealing means of plastically deformable strongmetallic matep 404 5N5 W References Cited UNITED STATES PATENTS rial areprovided between the piston rams and the rings.

425/77 425 77 Ishizuka................................ 425/77 10 Claims,3 Drawing Figures 2,94l,247 6/1960 2,995,776 8/196] Giardini et al......3,543,347 12/1970 PATENTED JUL 2 2 ms FIG. 1b

SHEET PATENTEDJUL 22 ms Q $35 a m m b Q m Q m N QZEQS o mzimzwm 2 cm on3 mm Q as E 2. ON om QM mm g cm om E. om cm A a: L O Q N at 3. g 3 (cm)X W07 HNIHJVN DEVICE FOR GENERATING HIGH PRESSURES AND TEMPERATURES Thepresent invention relates to a device for generating high pressures andtemperatures, in which in the pressure chamber of a high-strengthmetallic pressure container a charge or filling of different materialslaterally surrounded by electric insulating material is adapted to besubjected to pressure by means of two counter acting conical piston ramswhich are sealed relative to the pressure container, the respectivecharge or filling being adapted by electric current passing through thepiston rams to be heated up directly or indirectly.

A device of this type has become known in which the conically designedpressure container is lined with bricks which have to meet tworequirements, namely on the one hand to electrically insulate the twopiston rams relative to the pressure container and on the other hand toseal the high pressure chamber. Embedded in the brick lining is areaction vessel which receives the respective filling and which is madeof insulating material. This known device has the drawback that for eachtest or experiment the brick lining has to be applied anew. This,however, involves considerable work and costs in view of the complicateddesign of the high pressure chamber. Furthermore it is disadvantageousthat the limited deformability of the brick material does permit only alimited change of the high pressure volume under pressure.

It is, therefore, an object of the present invention to provide a devicefor generating high pressures and temperatures which will overcome theabove mentioned drawbacks.

These and other objects and advantages of the inven tion will appearmore clearly from the following specification in connection with theaccompanying drawings, in which:

FIG. la illustrates a maximum pressure device according to the inventionin non-loaded condition.

FIG. 1b shows the device of FIG. Ia under load.

FIG. 2 represents a prepared diagram for measuring and controlling thepressure, in which a test curve has been entered as an example.

The device according to he present invention is characterized primarilyin that the pressure container comprises at least two axiallysuccessively arranged rings which surround the cylindrical pressurechamber with a metallic wall and which consist of hightensile hardmetal, while between the rings and also between the rings and thesurrounding fitting of high-tensile steel there is arrangedpressure-resistant electric insulating material. The device according tothe invention is furthermore characterized in that the seals providedoutside the pressure chamber between the piston rams and the ringsconsist of a plastically deformable strong metallic material.

According to an advantageous feature of the invention, the electricinsulating material may consist of thin layers of mica or similarpressure-resistant substances.

Referring now to the drawings in detail, the cylindrical high pressurechamber 12, in which the not illustrated filling material is surroundedby a tube 11 of a plastically deformable electric and, if desired, heatinsulating material, preferably Whetstone, is enclosed by a metallicwall formed of three rings l-3 of high-tensile hard metal. While varioustypes of filling material may be used, merely by way of example suchfilling material may consist of a mixture of percent by weight of carbonto 30 percent by weight of nickel. Between the rings 1-3 of high-tensilehard metal consisting e.g. of 88 percent by weight of tungsten carbideand 12 percent by weight of cobalt, on the one hand and between therings and a fitting ring 4 which surrounds the rings 1-3 and consists ofhigh-tensile steel on the other hand, there is provided apressure-resistant electric insulating material in the form of thin micalayers 7. The installa tion of the mica layers 7 is carried out withhigh precision. During the assembly of the high pressure device, damageto the mica layers must be avoided. The fitting ring consists in anon-illustrated manner of a plurality of segments which together withthe hard metal rings 1-3 and the mica layers 7 are simultaneouslyinserted into a steel ring 5. This whole assembly is subsequentlywithout any change inserted into the main fitting ring 6 or matrix insuch a way that a maximum pressure preload will be obtained in the hardmetal rings l3.

According to a further feature of the invention, between the conicalpiston rams 8, 8a and the rings 1 and 3 surrounding the rams 8, 8a andprovided with a corresponding conical chamber there are arrangedcap-like seals 9, 9a which are located outside the pressure chamber 12and which consist of plastically deformable strong metallic material. Asan example for such material there may be mentioned steel containing0.40 percent by weight of carbon, 0.050 percent of phosphorus and 0.050percent by weight of sulfur, and having a tensile strength of from 6070Kp/mm The device according to the invention will, in view of themetallic seal, permit a long ram stroke. Furthermore, the device caneasily be made ready for a new test or experiment. To this end, the oldsample is in a simple manner pressed out of the cylindrical pressurechamber and new filling material is introduced. Also new sealing capsare in a simple manner placed upon the piston rams 8, 8a. These twosteps require little work and little time.

Inserted into the cap-like seals 9, 9a are conical intermediate punches10, 10a of hard metal by means of which the piston rams 8, 8a act uponthe charge or filling material. It is a well-known fact that the frontends of the piston rams which act upon the charge or filling materialare, due to the combined stresses caused by the high pressures andtemperatures, subjected to considerable wear. The intermediate punches10, 10a can in a simple manner together with the seals be exchanged. Inthis way it is not necessary after the front ends of the piston rams areworn down to exchange the entire piston rams, which means a considerablesaving in material.

Between the caps 9, 9a and the tube 11 there is provided a lead ring 13which is simple to produce. This arrangement will assure that during thepressure buildup during which the distance between the rams 8, 8a isreduced, no material can escape from the high pressure chamber 12because the gap between the intermediate punches 10, 10a and the hardmetal rings 1 and 3 becomes smaller and smaller. Inversely, the leadring will prevent that a portion of the material of the sealing caps 9,90 will, during the building up of the pressure, be squeezed into thehigh pressure chamber. In this way it will be prevented that highfrictional forces are generated between the punches 10, 10a on the onehand and the hard metal rings 1, 3 on the other hand whereby they mightbe destroyed or damaged. Furthermore it will be assured that thepressure will build up in the high pressure chamber 12 to the desiredextent.

The piston rams 8, 8a are so designed that during the change in theshape of the caps, in other words during the building up of pressure inthe high pressure chambet, the contacting surfaces between the rams andthe caps will remain constant to a major extent. In this way it will beassured that not too great a portion of the outer forces exerted uponthe rams 8, 8a will be consumed for changing the shape of the caps.According to an advantageous feature of the invention, the caps 9, 9awill during the building up of pressure exert an increasing lateralpressure upon the intermediate punches 10, 10a. In this way the extentto which these punches can be subjected to a load will be greatlyincreased in the direction in which they are subjected to their mainload.

If the caps 9, 9a are subjected to a major deformation, there exists thedanger that, in view of the nonhomogeneity of the material, the devicewill, when the pressure build-up starts, act eccentrically. This can beavoided in a simple manner by respectively inserting electricallyinsulating rings 15, a of synthetic material, e.g. the material soldunder the trademark Adipren, between the holding means 14, 14a of thepiston rams 8, 8a and the outer fitting members 4, 5, 6 of the highpressure chamber. These rings are during the pressure build-up uniformlyelastically deformed with relatively small forces. In view of the largeeffective lever arms, a centering of the main fitting 6 toward thepiston rams 8, 8a is forced. At the same time these rings serve assafety rings which are adapted to catch any material which might escapeunder pressure from the high pressure chamber.

Inasmuch as during the pressure generation there will neither materialof the caps 9, 9a to any material extent escape into the high pressurechamber nor material escape from the high pressure chamber, a pressuregauging and pressure measuring can be effected in the following manner:

The total force required for deforming the caps is, independent of therespective pressure build-up in the high pressure chamber, a definiteeasily measurable monotonic decreasing function of the stroke performedby the rams 8, 8a. It may be assumed that the stroke is A h, the totalforce generated by the press is K and the force absorbed by the caps isK K (A 11). There is then obtained for the medium pressure p in the highpressure chamber the equation:

P K n in which F designates the cross sectional surface of the highpressure chamber.

Thus, if during the high pressure tests, by means of an x,y-coordinaterecorder the total force K, which is adapted to be measured by means ofa load cell, is recorded as a function of the stroke A h, which strokeis adapted to be directly measured by means of a motion pick-up, and ifthis function is entered or plotted in prepared diagrams, for instance adiagram according to FIG. 2, which are placed on the x,y-recorder, it ispossible during the test at any time to read the pressure and, ifnecessary, to adjust or control the same. In the preprepared diagrams(see the stroke load diagram of the pressure measurement of FIG. 2), afamily of curves is plotted for discrete values ofp constant whichvalues where obtained on the basis of the above equation. The

family of curves can by means of electric resistance measurements onknown metals be checked at certain pressures. The family of cures is asto the illustrated extent only valid for load condition; for no load orexpansion another family of curves would have to be ascertained.

The heating of the high pressure chamber may be effected by suitabletubes of metal or graphite which are fitted into the insulatingWhetstone tubes 11 and are electrically conductively connected to therams 8, 8a. The rams are electrically insulated relative to the pressgenerating the force. If desired, it is also possible to operate thedevice with centrally inserted heated conductors or with direct heatingof the probes. The supply means for the current may in a non-illustratedmanner be simply connected to the holding means 14, 14a of the rams 8,8a.

As will be evident from the above, the device according to the presentinvention has several advantages over heretofore known devices of thetype involved. Thus, the device according to the invention makes itpossible with large starting volume of the filling material to producehigh pressures also with substances of high compressibility. Themetallic seals will, in view of their good deformability, permit a longstroke of the piston rams. During the high pressure tests, no electriccontact is established between the two piston rams through the hardmetal rings or the fittings therefor. Thus, the device according to theinvention is suited for carrying out maximum pressure syntheses within apressure range of from 30 to kbar. The device according to the inventionmay, for instance, be employed for producing diamonds, in which instancethe starting materials may be highly compressible.

Another advantage of the device according to the invention is seen inthe fact that the resetting of the device for a new test requires onlylittle time and work. It is merely necessary that new sealing caps areinserted. Still another advantage of the invention consists in that theconditions for a structurally simple lining of the high pressure chamberfor good thermal and electric insulation are given and also for simpleand reliable pressure measuring methods in the high pressure chamber.

The actual construction of the device according to the invention withrespect to the selection of the material and the geometry of the highpressure volume depends on the respective goal (pressure and temperaturerange, properties of the respective substance, as for instancecompressibility). Accordingly, the principle of the invention embracesnumerous possibilities of application and of design.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular showing in the drawings but alsocomprises any modifications within the scope of the appended claims.

What we claim is:

1. A device for generating high pressures and temperatures, whichincludes in combination: a high-strength metallic pressure containercomprising a pressure chamber adapted to receive a tubular member ofplastically deformable and electrically insulating material with acharge of material to be compressed therein, two oppositely locatedconical piston ram means arranged in axial alignment with each other andwith said pressure chamber and movable toward and away from each otherand said pressure chamber for respectively compressing a charge ofmaterial in a tubular member received in said pressure chamber andrelieving the thus compressed charge, electric current conveying meanselectrically connected to said piston ram means for heating a charge tobe compressed received in said pressure chamber, said pressure chamberbeing defined by at least two axially aligned annular members of highstrength hard metal, pressure resistant insulating material interposedbetween and electrically insulating said annular members from eachother, annular fitting means surrounding said annular members,additional pressure resistant mica insulating means permanentlyinterposed durably between the outer periphery of said annular membersand the inner peripheral surface of said fitting means and electricallyinsulating the same from each other, and strong metallic sealing meansarranged between said piston ram means and at least the respectiveadjacent one of said annular members.

2. A device for generating high pressures and temperatures, whichincludes: a high-strength metallic pressure container comprising apressure chamber adapted to receive a tubular member of plasticallydeformable and electrically insulating material with a charge ofmaterial to be compressed therein, two oppositely located conical pistonram means arranged in axial alignment with each other and with saidpressure chamber and movable toward and away from each other and saidpressure chamber for respectively compressing a charge of material in atubular member received in said pressure chamber and relieving the thuscompressed charge, electric current conveying means electricallyconnected to said piston ram means for heating a charge to be compressedreceived in said pressure chamber, said pressure chamber being definedby at least two axially aligned annular members of high strength hardmetal, pressure resistant insulating material interposed between andelectrically insulating said annular members from each other, annularfitting means surrounding said annular members, additional pressureresistant insulating means interposed between the outer periphery ofsaid annular members and the inner peripheral surface of said fittingmeans and electrically insulating the same from each other, strongmetallic sealing means arranged between said piston ram means and atleast the respective adjacent one of said annular members, each of saidpiston rarn means comprising an outer piston and an inner piston smallerthan said outer piston and inserted into the respective adjacentmetallic sealing means for acting upon a charge in said pressurechamber, each of said outer pistons being operable to act upon thepertaining inner piston, holding means respectively connected to saidouter pistons for holding the same, matrix means with a substantiallycylindrical inner wall surrounding said pressure chamber, andelastically deformable electrically insulating ring means arrangedbetween said holding means and said matrix means for centering saidholding means relative to said matrix means.

3. A device according to claim 1, in which said first mentioned and saidadditional pressure resistant electrically insulating material includeslayers of mica.

4. A device according to claim 2, in which said piston ram means andsaid metallic sealing means are so designed that during the deformationof said sealing means during the build up of pressure, the contactingsurface of the piston ram means with said sealing means remainssubstantially the same.

5. A device in combination according to claim 1, in which each of saidpiston ram means comprises an outer piston and an inner piston smallerthan said outer piston and inserted into the respective adjacentmetallic sealing means for acting upon a charge in said pressurechamber, each of said outer pistons being operable to act upon thepertaining inner piston.

6. A device according to claim 2, in which said inner pistons are ofhard metal.

7. A device according to claim 2, in which said metallic sealing meansare cap shaped so as to exert an increasing lateral pressure upon therespective adjacent inner piston in response to increasing pressureexerted by said piston ram means upon a charge in said pressure chamber.

8. A device according to claim 2, which includes two intermediate ringsof a plastically deformable material respectively interposed betweensaid metallic sealing means adjacent each of said piston ram means andthe respective adjacent end of a tubular member with a charge ofmaterial to be compressed within said pressure chamber.

9. A device according to claim 8, in which said intermediate ring is oflead.

10. A device according to claim 2, which includes matrix means with asubstantially cylindrical inner wall surrounding said pressure chamber.

1. A device for generating high pressures and temperatures, whichincludes in combination: a high-strength metallic pressure containercomprising a pressure chamber adapted to receive a tubular member ofplastically deformable and electrically insulating material with acharge of material to be compressed therein, two oppositely locatedconical piston ram means arranged in axial alignment with each other andwith said pressure chamber and movable toward and away from each otherand said pressure chamber for respectively compressing a charge ofmaterial in a tubular member received in said pressure chamber andrelieving the thus compressed charge, electric current conveying meanselectrically connected to said piston ram means for heating a charge tobe compressed received in said pressure chamber, said pressure chamberbeing defined by at least two axially aligned annular members of highstrength hard metal, pressure resistant iNsulating material interposedbetween and electrically insulating said annular members from eachother, annular fitting means surrounding said annular members,additional pressure resistant mica insulating means permanentlyinterposed durably between the outer periphery of said annular membersand the inner peripheral surface of said fitting means and electricallyinsulating the same from each other, and strong metallic sealing meansarranged between said piston ram means and at least the respectiveadjacent one of said annular members.
 2. A device for generating highpressures and temperatures, which includes: a high-strength metallicpressure container comprising a pressure chamber adapted to receive atubular member of plastically deformable and electrically insulatingmaterial with a charge of material to be compressed therein, twooppositely located conical piston ram means arranged in axial alignmentwith each other and with said pressure chamber and movable toward andaway from each other and said pressure chamber for respectivelycompressing a charge of material in a tubular member received in saidpressure chamber and relieving the thus compressed charge, electriccurrent conveying means electrically connected to said piston ram meansfor heating a charge to be compressed received in said pressure chamber,said pressure chamber being defined by at least two axially alignedannular members of high strength hard metal, pressure resistantinsulating material interposed between and electrically insulating saidannular members from each other, annular fitting means surrounding saidannular members, additional pressure resistant insulating meansinterposed between the outer periphery of said annular members and theinner peripheral surface of said fitting means and electricallyinsulating the same from each other, strong metallic sealing meansarranged between said piston ram means and at least the respectiveadjacent one of said annular members, each of said piston ram meanscomprising an outer piston and an inner piston smaller than said outerpiston and inserted into the respective adjacent metallic sealing meansfor acting upon a charge in said pressure chamber, each of said outerpistons being operable to act upon the pertaining inner piston, holdingmeans respectively connected to said outer pistons for holding the same,matrix means with a substantially cylindrical inner wall surroundingsaid pressure chamber, and elastically deformable electricallyinsulating ring means arranged between said holding means and saidmatrix means for centering said holding means relative to said matrixmeans.
 3. A device according to claim 1, in which said first mentionedand said additional pressure resistant electrically insulating materialincludes layers of mica.
 4. A device according to claim 2, in which saidpiston ram means and said metallic sealing means are so designed thatduring the deformation of said sealing means during the build up ofpressure, the contacting surface of the piston ram means with saidsealing means remains substantially the same.
 5. A device in combinationaccording to claim 1, in which each of said piston ram means comprisesan outer piston and an inner piston smaller than said outer piston andinserted into the respective adjacent metallic sealing means for actingupon a charge in said pressure chamber, each of said outer pistons beingoperable to act upon the pertaining inner piston.
 6. A device accordingto claim 2, in which said inner pistons are of hard metal.
 7. A deviceaccording to claim 2, in which said metallic sealing means are capshaped so as to exert an increasing lateral pressure upon the respectiveadjacent inner piston in response to increasing pressure exerted by saidpiston ram means upon a charge in said pressure chamber.
 8. A deviceaccording to claim 2, which includes two intermediate rings of aplastically deformable material respectively interposed between saidmetallic sealing means adjacent each of Said piston ram means and therespective adjacent end of a tubular member with a charge of material tobe compressed within said pressure chamber.
 9. A device according toclaim 8, in which said intermediate ring is of lead.
 10. A deviceaccording to claim 2, which includes matrix means with a substantiallycylindrical inner wall surrounding said pressure chamber.